Touch panel and method of manufacturing the same

Abstract

An inexpensive touch panel securing a predetermined active area and yet being downsized is provided. The touch panel includes an upper substrate having an upper conductive layer beneath its lower face, and a lower substrate having a lower conductive layer on its upper face opposite to the upper conductive layer at a given interval. Pressing and heating a adhesive layer made from thermoplastic resin and hardener allows bonding the upper and lower substrates together. The touch panel is thus constructed.

What is claimed is:  
     
         1 . A touch panel comprising: 
 an upper substrate having an upper conductive layer beneath a lower face thereof;    a lower substrate having a lower conductive layer on an upper face thereof;    a adhesive layer for bonding the upper substrate and the lower substrate together at a predetermined spot, the adhesive layer comprising thermoplastic resin and isocyanate hardener and having a width ranging from 0.5 to 2.5 mm.    
     
     
         2 . The touch panel of  claim 1 , wherein at least one of the upper substrate and the lower substrate includes the adhesive layer formed by printing.  
     
     
         3 . The touch panel of  claim 1 , wherein a thickness of the adhesive layer ranges from 5 to 50 μm.  
     
     
         4 . The touch panel of  claim 1 , wherein an modulus of elasticity of the adhesive layer ranges from 10 4  to 10 9  Pa at room temperature.  
     
     
         5 . The touch panel of  claim 1 , wherein the isocyanate hardener includes at least two isocyanate groups in one molecule.  
     
     
         6 . The touch panel of  claim 5 , wherein an additive amount of the isocyanate hardener ranges from 1 to 10 in weight vs. an amount of the thermoplastic resin in weight of  100 .  
     
     
         7 . The touch panel of  claim 1 , wherein the thermoplastic resin of the adhesive layer is at least one of acrylic resin and polyester resin.  
     
     
         8 . The touch panel of  claim 1 , wherein an average molecular weight of the thermoplastic resin of the adhesive layer is at least 2×10 5 .  
     
     
         9 . The touch panel of  claim 1 , wherein the adhesive layer is shaped like a frame, and corner portions of the adhesive layer are narrower than other portions.  
     
     
         10 . The touch panel of  claim 1  having a manufacturing method comprising the steps of: 
 printing the adhesive layer on at least one of the upper substrate and the lower substrate;  
 placing the upper conductive layer opposite to the lower conductive layer; and  
 bonding the upper substrate and the lower substrate together by one of heating plus pressing the adhesive layer and only pressing the adhesive layer.